In late 2007, I found myself in the offices of the Swiss far-right party, the Swiss People's party (SVP), led by Christoph Blocher in Zurich. Then promoting a hardline anti-immigration manifesto, Blocher and his plausible young aides were keen to insist they were not racist. But walking through the offices, the voluble press officer was suddenly silenced. One of the staff had posted a series of cartoons of racial stereotypes on the wall, including one of der Juden – the Jew.

Kaminski – who was a member of an antisemitic party in his early adult years, and appears to have misremembered, if not misrepresented, his opposition to a memorial for the Jews murdered by Poles at Jedwabne – has been defended by the editor of the Jewish Chronicle and feted at a lunch by the Conservative Friends of Israel. Zile, meanwhile, has conducted himself with a somewhat disingenuous mien of being hurt that a democracy like ours could point a finger at his party.

I say disingenuous because the history of Zile's party – like Kaminski's own political record of membership of an unashamedly extremist party – is far from free of accusations of involvement with antisemites. Indeed, according to the Stephen Roth Institute's study of antisemitism in the Baltic republics a decade ago, one of the chief activists in Zile's party, Leonards Inkins, was responsible for republishing, at his own expense, Baigais Gads, a deeply antisemitic work first published in 1942 during the Nazi occupation of Latvia, which accused Jews of being behind the Soviets' atrocities. This was scandalous enough in Latvia that the party, eventually, was obliged to expel him.

For Kaminski's part, he has been quoted as saying that no apology should be forthcoming to the Jews of Jedwabne – until Jews had themselves apologised for their part in Soviet atrocities during the Soviet occupation.

There is a point here, reinforced by the nature of too many of the blogs and comments that have appeared defending Kaminski and Zile, and defending the Conservative party's relationship in Europe with them. For while some have defended Kaminski out of political expediency, there are others who share a common strain of hostility towards Jews.

It comes not from the strain of antisemitism that seems to be most discussed today – visible in some areas of Islamist discourse, or in the claims that left anti-zionism or criticism of Israel represents, so critics say, its own kind of antisemitism. It derives, rather, from an older and more virulent strain. Its narrative – still strong in regions like the Baltic republics and parts of eastern Europe – argues, as the Nazi propagandists did, that the Jews were behind the Bolsheviks and therefore responsible for their crimes.

In truth, it is an antisemitic tradition that predates even the Nazis, first propagated by the White Russians. It was picked by the early theorists of national socialism in Germany and later by the prominent Nazi propagandist Ulrich Fleischhauer, among others.

What Kaminski and some supporters of Zile's party represent is an echo of those attitudes. It is visible, in the Latvian case, in the constant attempts to make an equivalence between Soviet atrocities and Nazi-genocidal crimes that saw the slaughter of more than 60,000 Jews simply because of who they were. It seems to argue that because the Soviets were bad, the motives of those Latvians who volunteered for the Waffen-SS are excusable.

But what is really worrying is that such attitudes exist here in the UK as well. When David Miliband made his speech criticising the Conservative relationship with Kaminski and Zile, the comments posted online by some Conservative supporters have either defended those members of Zile's party who supported the commemorative march of the Latvian SS, because they fought the Bolsheviks, or, more scandalously, suggested that Miliband had no "right to comment on Nazism", as he was a Jew with "Bolshevik grandparents".

All of which leads to the question: why individuals and organisations usually so sensitive to suspicions of antisemitism – including the Conservative Friends of Israel and Israel's ambassador to London, Ron Prosor – seem to be blind in this case.

Editor's note: This article was amended at 11:00am on 9 October to remove a reference to Stephen Pollard as the "Tory editor of the Jewish Chronicle". As Pollard himself points out, he has a long record as a Labour voter.